Photo-electric tube



NOVf 1, 1932- H. H. GEFFCKEN ET AL 1,885,819

PHOTO ELECTRIC TUBE Filed Deo. '7. 1928- Patented Nov. 1, 1932 taaie fAF F E f IIEINEICH H. eEEEcKENfAND-IIANS E. RICHTER, E LEIPZIG, GERMANYmicro-ELECTRIC TUBE Application led December 7, 1928, Serial No.

' Our invention relates to photo-electric tubes of the kind comprising asealed tube which-may be .of glassfquartzl or other suitable materialandfcontaining afilm electrode of light sensitive material (e. g.,potassium, sodium' or the' like) and a second electrode. for collectingthe electrons emitted by the film electrode when the latter is subjectedto .e theinfluence oflight.r`- n 1U More ydefinitely stated, the objectof our invention is a photo-electric tube particularly'adapted for.attachment to various apparatus where only narrow spaces,v crevices orchannels are left for the insertion of the i photo-electric tube. Thephoto-electric tube disclosed in this case is of such structure asv torequire extremely small space. Thisis,` generally speaking, achieved byarranging the electrodes on `one side and all terminals on the: otherside-of the tube and opposite the side from which the light rays fall onthe tube. It is possible in thisjway to construct. a very small andeflicienttube which may be inserted into slmallrspace-in an apparatuswhere the tube is 'required7 being attached to the apparatus not unlikethe human eye isattached to the-head. and the light rays will fall onvthe tube without obstruction since all terminals are'providedcollectively in the rear of the tube. It will be obvious that suchstructure of a photo-electric tube will be very valuable in many cases.The usual photo-electric tubes have terminals arranged separately in acertain angle to each other rand require a relatively large space. Thus,by collectively arranging the electrodes on one side (where the light isreceived) and bv collectivelv arranging the terminals on the oppositeside. we succeeded to provide a photo-electric tube of great utility notdisclosed in any prior invention.

Our invention will be best understood by reference to the followingdescription which f' should be read in connection with the accompanyingdrawing.

In this drawing, Figure 1 represents a diagrammatic view of aphoto-electric tube, the light sensitive film Yof which is produced byApouring the Y Figure 3 represents `a 324`,4=70,'and in Germany December9, 192'?.`

photo-electric material in liquid condition into the tube. f Y

Figure 2 represents 'a diagrammatic view ofv photo-electric tube, thelight sensitive film v'of which is produced by pouring the 55'photo-electric material upon a plate provided in the interior ofv thetubeI and carrying a tight meshy metallic net.-

diagrammatic view of a photo-electric tube, the light sensitive film ofwhich is produced by precipitating the lphoto-electric material invaporized condition upon a recess in the walls of the tube which risescentrally'into the tube.

Referring particularly to Figure-1, the tube 1V contains an anodeelectrodey Zand a cathode lightysensitive filmL 3. The light. raysstrikethe tube in the direction of the arrows 4.' Both of the terminalwires 5 and 6 of the cathode light sensitive film and of 70 the anodemember, respectively, are arranged on the same side of the tube andopposite tothe side exposedto the light rays.

It will be appreciated that the structure described above possesses manyadvantages over photo-'electric tubes known aty the present time,whichare usually provided `with a separate lateral stalk containing theanode terminalV wire. 'Consequently, the space required by theselphoto-electric tubes-must be relatively large; The advantages of ourinvention will be very valuable in many cases.

v As shown in Figure 1, the tube l is provided with a conduit?l forsupporting inl its interior the anode terminal. This conduit S5 is'alsoarranged on the tube opposite the side exposed to the light rays. Theconduit 7 is adapted to be heated after the light sensi-, tive lilm ispositioned in the tube, and this heating can be accomplished withoutheatl -ingthe light sensitive lm. All precipitates can, therefore, beeasily removed and a sui"- ficient insulatingportion is produced in theinterior ofthe tube. `The conduit 7 extends into the interior of thetube beyond the film 3, in order to prevent theliquid photo-electricmaterial from entering the conduit 7 during the manufacturing processwhen applying the liquid material to form the film.

Referring-to Figure 2, the light ysensitive film is in this case appliedto a supporting plate 9. The plate is for this purpose provided with atight meshy net l of copper, silver or another metal, adapted to receiveand to absorb the liquid photo-electric mate rial. When the liquidphoto-electric material is brought in4 contactL with thenet 10, this netwill receive and will absorb thefmaterial owing to cohesion andcapillary attrac- 0 tion7 and will be uniformly coated 'withV a tightlight sensitiveilm.l

An especial advantage of the last described photo-electric tube residesin the fact that' very small quantities of photo-electric mates rial arerequired and" that the materialv is applied in liquid (and not invaporizedcon dition). The possibility of inconveniences;r

whichmay be caused by'undesirable.precipitates of vapor-izedp11oto-eleotricmater1al as usually applied, isconsequently appreciably"reduced. y V,Referring to Figure 135 the tube 'lfisI pro-V vided with arecess 171,. risingA centrally into the interior of the tube'. ppositethe 'top 2 5'. of the recesslll, withimthe tube-,there is ar` rangedaroug'hfmeshy.- net 12 of metal, closely attached to .the inte-riorsurfaceeofthe front v portion ofthe tube and connected'to'theanodeterminal wire.- The netfl2.serveseasanode electrode. The lightsensitivefilm i-s-applied to the topfoflthe' recessll within the tubebyifeeding-the photo-electric'material in vapor-f ized state into the tubeandby simultaneously heating, the outer wall of-'th'etubefandicooling:

the recess l'l by a curlrent=l of coldairorin an other suitablemanner'.v

Numeral. .13 desigf' nates` a'suitable base.v

scribed embodiment ofourinvention reside in the fact that extremelysmall quantities of' photo-electric materialane required. for pr-o-Aduring the light sensitivevlm and that the thek vapor-ized.- material'willi only .precipitate on the cooled recess withoutv any otherprovision, .and this work and-safely.

Numerous changesfcanVoi course, be made inthe' structure and inthefarrangement of details of our invention without departing ptherefore,.wantto have it understoodthat we desire to applythe infromits spirit.I We,.

vention onlysubject to the limitationsasex-l pressed in` the Aclaimswhich `follow:

l.. A photo-electric tube havingafsealed en-v velope; a light. sensitivecathode; -an anode-v electrode positioned within saidlenvelope in theend to be exposed to the light rays; 'aV terminall connected to said:cathode artermif "==na1fconnected`to said anode; electrode;"and

can be performedeasily a conduit extending into said envelope throughsaid cathode and separately mounting said anode terminal.

2A photo-electric tube comprising a sealed envelope a light sensitivecathode electrode to be exposed to light rays received from. one side oisaid. tube; an anode electrode; a' terminallconneeted tosaidcathodeelectrode; and aterminal connected to said anode electrode, said lastmentioned termina-l extending througbfsaid envelope through an openinginsaid cathode electrode and through thsideofsaid envelope opposite saidone s1. e.` Y Y 31A photo-electric tube v comprising a sealed :envelopeh aving. api at, window. alight sensitive cathodeelectrode an anodeelec-` trode a terminal`` connected? tofsaid. cathode electrode.; aterminaliconnectedto saidV anode. electrode, Y said last mentioned'.terminal ex-y tending yinto said envelope i'fhrou-ghon,A ov ening.. in-saidfcatliode electrode, saidfcathode, and anode. electrodes beingparallel.4 to saidl window, and saidanodeLa-nd cathodetermi nalsextending into said'en'veloperon thes-ide opposite said Window. f r

vt'. A photo-.electric tube comprisingk afl sealed' envelope havinga twindow;` ai light. sensitive cathode electrode; an anode elect? trode.terminalconnectedit'o said cathode electrode; a terminal'connectedtosaid'anode electrode; saidterminals projecting through y. the lsides ofsaid`- envelope opposite said Win-A dowsfaud saidelectrodes beinginterpose'dbefv tween `,said Windows andthe sidetli'rougli whichsaiditerminalsprojectand extending at'A rightangles .to tlejpath ofLtliebeam of light; whereby substantially allltlie light enteringfrom said-Window Iis* impinged upon and: ab-

sorbedbyfsaid cathode electrode` y p v l Inrtestimony whereof'weaiiixgour signa-f tures.v i

